I don't think Mariah is the best singer of this decade. Is a matter of taste honestly. In my opinion the tone of the voice is also important and I prefer Adele's tone over Mariah's. The sound of Adele's voice when she riches the high notes sounds a lot better to my ears than Mariah's. And like Mariah Adele also has perfect control over her high and lows she is technically perfect as much as a artist can be. And to be honest I also prefere Xtina high notes over Mariah's. I like Mariah but there is no way her voice is better than Adele's. To be honest I would compare Adele to the great Aretha Franklin and Tina Turner I wouldn't compare her voice to Mariah's. I don't know really how to explain but certain artists blow up the room not only because of their voice but the energy and emotion they are able to make you feel with their voice. Adele is one of those very few artists to me she is visceral like Aretha and Tina. But like I said is a matter of taste and this is just my opinion several will think differently and probably a very few will agree.

We are not talking about personal taste, we are talking about facts and Mariah is better

Imagine being Lana on stage, you crying because no one likes you and you twirl around while combing your hair loving all the fans you see in front of you......and then in the corner of your eye you see Kim and her disgusting family watching you.